Each year a specific aspect of water is highlighted while observing International World Water Day (March 22); this year’s theme was “wastewater”, which is defined as any water that has been adversely affected in quality by anthropogenic influences and as a result of domestic, industrial, commercial and agricultural activities.
In recent decades, population growth, accelerated urbanisation and economic development have resulted in an increase in the quantity of wastewater and the overall pollution load being generated. Most of our freshwater sources are under threat. When public awareness of pollution is limited, the cost of pollution to our health and the ecosystem is huge. The victims are generally the poor or socially vulnerable communities, and the end result is a high financial burden on the community and government.
- Globally, over 80% of the wastewater generated goes back to the ecosystem without being treated or reused.
- 1.8 billion people use drinking water contaminated with faeces which increases their risk of contracting cholera, dysentery, typhoid and polio.
- 663 million people still lack access to improved drinking water sources.
- In India, about 29,000 million l/day (mld) of waste water is generated from Class-I cities and class-II towns, out of which about 45% (about 13,000 mld) is generated from metro cities alone. A collection system exists for only about 30% of the wastewater through sewer lines, while treatment capacity exists for about 7,000 mld.
- By 2030, the global demand for water is expected to grow by 50%. Most of this demand will be in cities. In low-income areas of cities/towns within developing countries, a large proportion of wastewater is discharged directly into the surface water drain, without or with limited treatment. Traditional wastewater treatment plants may not remove certain pollutants.
- Industrial water consumption accounts for 22% of the global water used. The industrial sector in India discharges around 30,730 million cubic metres of effluents, without proper treatment, into waterbodies. Unfortunately, most common effluent treatment plants are not performing satisfactorily due to improper operations and maintenance.
- Run-off from agriculture fields is another major source of pollution.
- India, with 17% of the world’s population, 4% of water resources and 2.4% of land area, extracts water significantly for various developmental purposes. Hence, the water flow or storage capacity of water bodies has declined substantially, adversely affecting their waste assimilation/sink functions.
- There is sufficient evidence to suggest that the problem, though complex, is solvable. While it is not realistic to aim for zero water pollution, a level of socially acceptable pollution, respecting the integrity of ecosystems and service provision, can be reached.
- At the national and regional levels, water pollution prevention policies should be integrated into non-water policies that have implications on water quality such as agriculture and land use management, trade, industry, energy, and urban development.
- Water pollution should be made a punishable offence.
- The effectiveness and power of the “polluter pay principle” should be considered.
- At the local level, capacity building enables the community to make decisions and disseminate them to the appropriate authorities, thus influencing political processes.
- Market-based strategies such as environmental taxes, pollution levies and tradable permit systems should be implemented, and can be used to fight against or abate water pollution. Incentive mechanisms such as subsidies, soft loans, tax relaxation should be included in installing pollution management devices.
- In industrial pollution management, technological attempts should be made through cleaner production-technology. Sophisticated pollution management technology developed overseas should be introduced in India. The application of eco-friendly inputs such as bio fertilizers and pesticides in agriculture and the use of natural dyes in textile industries can reduce the pollution load considerably.
Since fresh water is increasingly getting scarce, wastewater generated in urban areas can be used for sub-urban agriculture, industry, and even sanitation and certain domestic applications after treatment. Wastewater need not be a burden any longer but an asset instead.